FIELD OF THE INVENTION
This invention is generally concerned with stabilizing the catalytic activity of those zeolite catalysts employed in (1) fluid catalytic cracking, reforming, etc. processes used in the petroleum industry (as well as in various chemical manufacturing processes that do not involve petroleum products), (2) fixed bed catalytic processes (involving petroleum products or non-petroleum products), (3) fluid bed catalytic processes (involving petroleum products or non-petroleum products) or (4) so-called deep catalytic cracking ("DCC") (involving petroleum or non-petroleum products). Such zeolite "stabilization" implies a reduction in the rate at which a given zeolite's catalytic activity is lost due to such factors as thermally induced damage to that zeolite's molecular structure, as well as accumulation of coke, sulfur and/or undesired metals on its catalytically active sites. More particularly, this invention is concerned with stabilizing zeolites against these harmful effects by chemically reacting them with clay materials (rather than merely physically mixing them with such materials) through the use of certain alkaline, phosphate-containing compounds, certain pH conditions and certain reaction time parameters.